miatamike203

So i built my MS2 the other night and tried to power it up today in the car and i got nothing but sizzle sizzle. I found R37 burned, D10 sizzling and Q12 every time i powered it on . I went and check all the wire and relays everything is normal. Now the one big problem i am also having is the little info on this so called needed condenser that Mega manual says is needed on the coil power wire. It calls for a 25 microfarad condenser but no info on voltage. =[

Does any one know why these 3 things start to burn???


I tried a 35v 47microfarade capacitor before it burned.

Also i grounded all the ground wires on the MS2 to the engine the and i use one ground wire to the ford EDIS. So can someone tell me if i did something wrong.

Joe Perez

iTrader: (8)

Well, first things first. If you re-used the Miata's stock coil wiring, there's already a cap on the supply line to the coils. For the time being, forget about adding anything extra until we get the board to stop emitting fire and components. Also, 47uf is nothing. Those of us running COPs are using huge values- I can't recall the exact values I used, but I think it was 2x 4,700 uf in parallel (9,400 uf equivalent) at probably 35v. (I think I just bought two of the largest caps RadioShack had.)


Now, onto snap, crackle and pop...

R37 is the 0.05 ohm resistor that's used as a current-sense shunt in injector circuit 2. Its purpose in life is to help prevent things from blowing up when you have a short-circuit across an injector, by signalling Q15 to remove the gate drive current from Q5 when it detects more than 14 amps coming down that line.

Q12 is part of the flyback-damping circuit for INJ2. Again, it's there to prevent harm, not to cause it.

And D10, well, that guy is in series with the 12v coming into the board just before the regulator. It is after hole S12, but before hole S12C.

I'm wondering if you have multiple problems...


For starters, do you have any wires connected to point S12C on the main board?


Are R20, Q5, Q15, Q11, D7 and D20 all installed correctly and without any solder blobs? If I turn my head and squint just right, I can see a potential path for some damage there, although worst-case should be a short from just before D10, not after it...


How about D12, C16 and U5- are all those guys straight and clean? A short across any of the three would nuke D10. So would a short across both D9 and either C17 or C18, but that seems improbable.

Pictures, man! Nice, clear, high-resolution pictures.

miatamike203

I checked for solider blobs and got non, im also running this on a SR20 with the SR20 coils. I have done everything that DIY lists for the ms2 to work with the ford EDIS system. Only the r35 is burned, q12 and d10 just sizzle at one of the solider points.

Also could i buy a already built MS1 and use my MS2 daughter board to make it a MS2?


No pic sorry i have no camera.

Joe Perez

iTrader: (8)

Ah.

Well then.

Uhm...

SR20Turbo.net?





?!

What, precisely, is doing the sizzling? Is it the device, the board, or the actual solder joint itself?



Yes. There are a couple of modifications required before you install the MS2 processor, but they're well documented on the MS2 site.


Ok... Could you perhaps commission a local artist to create a portrait of it, preferably in the naturalist style of Ilya Yefimovich Repin or Jean-François Millet?

miatamike203

D10 has a sizzle on the solider joint on the non banded side and q12 i dont remember.

miatamike203

Sorry i forgot to add, it sizzles and arcs on the D10.